JPH05194770A - Surface-coated plastic article - Google Patents

Abstract

PURPOSE:To produce the title article excellent in the resistances to scratch, abrasion, and chemicals by forming a silicon compd. layer by plasma polymn. on the surface of a plastic substrate and forming an SiOx layer on the above- formed layer. CONSTITUTION:The title article is produced by forming a layer having a thickness of 0.1-10mum and a ratio of the number of the carbon atoms to the silicon atoms of 0.1-3 by plasma polymn. of a silicon compd. monomer on the surface of a plastic substrate and forming an SiOx (wherein x is 1.5-2.0) layer having a thickness of 0.1-3mum on the above-formed layer. The latter layer is pref. formed by sputtering or the plasma CVD method, sputtering being esp. pref.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention has excellent scratch resistance, abrasion resistance, chemical resistance, charging characteristics and the like due to the formation of a hard coating on the surface thereof, and various optical materials, optical recording materials, window glass, etc. A plastic product suitable for use as

[0002]

2. Description of the Related Art Plastic products, particularly molded products made of transparent plastic materials such as polycarbonate and polymethylmethacrylate, are used as decorative or inorganic glass substitute materials in the fields of vehicles, ships, aircraft construction, etc. It has come to be widely used as a plastic mirror, a lens, various optical materials, optical recording materials, and the like by taking advantage of the properties.

Generally, plastic materials are
The surface is easily scratched, and the transparent plastics material is subjected to a hard coat treatment, that is, a transparent coating having a high hardness, in order to prevent deterioration of aesthetics and transparency due to scratches. There are roughly two known methods for applying these hard coats. One is a dry coating method typified by a vacuum vapor deposition method, a sputtering method, a plasma CVD method, a plasma polymerization method and the like. The other is a wet coating method in which the solution is applied and then heat-cured or photo-cured, and organic (melamine resin-based, urethane resin-based,
There are alkyd resins, UV-curable acrylates, etc.) and silicones (organosiloxanes).

In the sputtering method, it is possible to impart sufficient hardness to the film itself, but since the intrinsic stress is large, it is not possible to obtain sufficient adhesive strength if the film is made thick, and if the film thickness is thin, Since the surface of the plastics, which is the base material, is affected by the hardness of the film, even if the hardness of the film itself is high, the function of preventing scratches is poor. Plasma polymerization method and plasma CVD
According to the method, it is possible to obtain a film having excellent adhesion to the surface of plastics depending on the film forming conditions, but it is inferior to the sputtering method in film quality such as hardness and denseness.

In the vacuum deposition method, there are problems that it is difficult to control the element composition ratio to obtain a SiO ₂ composition, and that the film density and the adhesiveness to the plastics surface are inferior to the sputtering method. On the other hand, in the wet method, the intrinsic stress of the film is small and the adhesiveness to the plastic surface is good, but the film density is low and the scratch resistance is inferior to the conventionally used glass. The use of was not practically sufficient.

In order to make up for the disadvantages of these various film forming methods, attempts have been made to improve the adhesiveness and scratch resistance of the film by combining two or more film forming methods. Japanese Unexamined Patent Publication No. 60-238331 proposes a method of forming a plasma polymerized film having a crosslinked structure on a plastics molded product which has been hard-coated with a crosslinkable resin film which has been subjected to an active energy ray irradiation treatment. .. In addition, JP-A-6
Japanese Patent Application Laid-Open No. 3-81033 proposes a method of forming a coating film made of SiO _{2 on} a plastic molded product through a thermosetting organic polymer film containing fine particles of inorganic oxide by a dry method such as a vacuum deposition method. There is.

[0007]

However, in the method of forming a plasma-polymerized film having a crosslinked structure on a plastics molded article which has been hard-coated with a crosslinkable resin film which has been subjected to an active energy ray irradiation treatment, plasma polymerization is used. Although the film has smaller specific stress and better adhesion than a sputtered film, it is inferior in film hardness, denseness, etc., and therefore inferior in scratch resistance and abrasion resistance. In addition, in a method of forming a film made of SiO _{2 on} a plastic molded product through a thermosetting organic polymer film by a dry method such as a vacuum deposition method, the plastic molded product is coated with the thermosetting organic polymer film. In that case, the film forming process usually requires a process time of 2 to 3 hours in order to impart sufficient adhesiveness,
Moreover, the process management is very severe. For this reason, when a film forming step by a dry process is further added, the total cost is significantly increased, and the object of the product is extremely limited. Moreover, the adhesiveness between the films is inferior to the film formation process by the consistent dry method, which is not practical.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems, and have found that the problems can be solved by forming a special multi-layer coating, and arrived at the present invention. did. That is, the gist of the present invention is a surface-coated plastic product in which the following A film and B film are laminated in this order on the surface. A film: A plasma polymerization film formed by plasma polymerization of a silicon compound, having a film thickness of 0.1 μm to 10 μm, and having an atomic ratio of contained carbon to silicon in the range of 0.1 to 3. B coating: SiOx (x = x = 3 μm in thickness)
1.5-2.0).

The present invention is a product in which the above A film is provided on the surface of a plastic product, and the atomic ratio of carbon to silicon contained in the A film is in the range of 0.1 to 3. It is necessary to be in. That is, if the atomic ratio of carbon and silicon contained is less than 0.1, sufficient adhesive strength between the A coating and the surface of the plastic cannot be obtained, and the atomic ratio of carbon and silicon contained is not sufficient. When it exceeds 3, sufficient adhesive strength between the A coating and the B coating cannot be obtained, which is not preferable.

The silicon compound which can be used in the present invention is preferably a silicon compound containing a carbon atom or a silicon compound containing a carbon atom and an oxygen atom or a nitrogen atom, and specific compounds include, for example, 1,1,3. , 3-tetramethyldisiloxane, 1,1,3,3-tetramethyldisilazane, pentamethyldisiloxane, hexamethyldisiloxane, hexamethyldisilazane, heptamethyldisilazane, 1,3-dimethoxytetramethyldisiloxane ,
1,3-diethoxytetramethyldisiloxane, hexamethylcyclotrisiloxane, hexamethylcyclotrisilazane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,1,3,5 , 5,5-heptamethyltrisiloxane, octamethyltrisiloxane,
1,3,5,7-tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, 1,1,
1,3,5,7,7,7-octamethyltetrasiloxane, 1,1,3,3,5,5,7,7-octamethylcyclotetrasilazane, tris (trimethylsiloxy) silane, decamethyltetrasiloxane Etc., the following general formula (I)

[0011]

## STR1 ## This is represented by R ¹ nSiR ² _4-n (I). In the formula, R ¹ is ^one selected from an alkyl group, an alkenyl group, an aryl group, a halogen group, an amino group, a mercapto group, a cyano group, an isocyano group, a vinyl group, a methacryloxy group, an epoxy group and a hydrocarbon group having a glycidoxy group. Alternatively, they may be two or more and may contain chlorine and fluorine atoms. R ² is one or more selected from a hydrogen atom, an alkoxy group, an alkoxyalkoxy group, a phenoxy group, an acetoxy group and a chlorine atom, and n is 0 to 4. Specific examples include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, methylsilane, dimethylsilane, trimethylsilane, tetramethylsilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, tetraethoxysilane, and methyl. Many other compounds such as triethoxysilane, dimethyldiethoxysilane and trimethylethoxysilane can be mentioned. These silicon compounds may be used alone or in combination of two or more. Since plasma polymerization of these compounds is carried out in a gas phase, compounds that are easily vaporized at room temperature are desirable, but compounds that are easily vaporized only by heating can be used by appropriately heating the compound and the polymerization apparatus. In order to increase the oxygen content in the film, these raw materials may be mixed with O ₂ or N ₂ O as an oxygen source.

Before forming the B coating on the A coating, it is desirable that the surface of the A coating be surface-treated with O ₂ or N ₂ O gas plasma. Regarding the processing conditions, the optimum conditions differ depending on the monomers used, plasma polymerization conditions, etc., and should be determined experimentally for each film-formed product. As a method for forming the SiOx (x = 1.5 to 2) which is the B film, a sputtering method or a plasma CVD method is preferable, but a sputtering method is particularly preferable.

A plastic product having a plasma polymerized film formed by plasma polymerization of a silicon compound is sputtered with Si.
When forming an Ox (x = 1.5 to 2) film, the formed high-hardness sputtered SiOx (x = 1.5 to 2) film is firmly bonded to the plasma polymerized film, and the plasma polymerized film is formed. It is bonded to the plastics which is the base material through. Therefore, the large stress of the sputtered SiOx film is not directly applied to the plastics substrate, so that the adhesiveness of the sputtered SiOx (x = 1.5 to 2) film can be remarkably improved. The thickness of the plasma polymerized film is from 0.1 μm to
It is 10 μm, preferably 0.5 μm to 5 μm. 0.
When the thickness is 5 μm or less, SiO (x
= 1.5 to 2) When a sputtered film is formed, sufficient adhesiveness cannot be obtained, and when it exceeds 5 μm, cracks are likely to occur. The thickness of the SiOx (x = 1.5 to 2) sputtered film is 0.1 μm to 3 μm, preferably 0.2 μm to 1 μm. If it is 0.2 μm or less, sufficient scratch resistance cannot be obtained, and if it exceeds 1 μm, cracks are likely to occur.

[0014]

EXAMPLES The present invention will be described in detail with reference to Examples.
The present invention is not limited to the examples below.

Example 1 A polycarbonate resin substrate (manufactured by Tsutsunaka Plastics Co., Ltd.) was set on the cathode in a parallel plate type plasma polymerization apparatus, and tetraethoxysilane gas and N 2 were added under reduced pressure.
_The pressure was increased to 650 while aeration with ₂ O gas at a molar ratio of 1: 2.
Adjust and hold at mTorr, 110KHz, 0.5W / c
Plasma was generated by applying a low-frequency power of m ² to discharge, and the substrate surface was plasma-treated for 60 minutes to obtain a polycarbonate resin substrate having a plasma polymerized film. The substrate temperature was maintained at about 50 ° C. during the plasma polymerization (the substrate temperature here is the temperature of the cathode surface on which the substrate is placed, and hereinafter the substrate temperature in the plasma polymerization shall mean this temperature). .. This was set in an RF planar magnetron type sputtering device (SMH-2306 manufactured by Nippon Vacuum Technology Co., Ltd.), SiO ₂ was used as a target, and an Ar gas atmosphere was set to 10 mTorr and 10 mTorr.
RF (13.56 MHz) sputtering was performed at 00 W for 20 minutes. The substrate temperature was kept at about 95 ° C. in the sputter (the substrate temperature here is the temperature of the surface holding the substrate, and hereinafter the substrate temperature in sputtering means this temperature). The following characteristic test was conducted on the obtained surface-treated substrate, and the results are shown in Table 1.

Characteristic test items and method 1. Initial adhesion of film A cross-cut adhesion test was performed. The cross-cut adhesion test referred to here is that a sputtered film and / or plasma polymerized film coated surface is first laid with a steel knife so as to reach the substrate at 1 mm intervals, and the next cellophane tape (Nichiban Co., Ltd.)
It is a test method in which a product made in a width of 24 mm) is closely adhered, and the film is rapidly peeled in the direction of 90 ° C. to see the presence or absence of peeling. Each sample was tested and the number of sheets that did not peel was shown. 2. Scratch resistance (1) Scratch resistance of steel wool Surface treatment with # 000 steel wool Rubbing the surface of the substrate, ○ -No scratch even with strong rubbing △ -Slight scratch with rubbing strongly × -Even with strong rubbing It was displayed that it was scratched. (2) Taber Abrasion Test According to ASTM D1044, a test was conducted with a wear wheel CS-10F and a load of 500 g, and ΔHaze before and after the test was measured after 500 abrasion cycles. Here, the definition of ΔHaze is ΔHaze = Haze after the test−Haze before the test. 3. Weather resistance test After a 120 hour test according to JIS A1415 using a weather meter (WE-SUN-HC manufactured by Suga Co., Ltd.), an adhesion test by a cross cut test was performed. The number of sheets that did not peel is shown in the table. Example 2

Using the same substrate and plasma polymerization apparatus as in Example 1, under reduced pressure, hexamethyldisiloxane gas and N ₂ O were used.
The pressure is 150 mT while aerating gas at a molar ratio of 1: 2.
Adjust and hold at orr, 110KHz, 0.5W / cm ²
Plasma was generated by applying low-frequency power to and discharging the plasma to subject the substrate surface to plasma treatment for 60 minutes to obtain a polycarbonate resin substrate having a plasma polymerized film. Subsequently, the pressure was adjusted to 250 mTorr while maintaining the pressure at 250 mTorr while ventilating only N ₂ O gas under reduced pressure in the same device.
Plasma was generated by applying a low frequency power of 0.25 W / cm ² to cause discharge, and the substrate surface was plasma-treated for 3 minutes. The substrate temperature was kept at about 50 ° C. during plasma polymerization and plasma treatment with N ₂ O gas. A sputtered film was formed on this under the same conditions as in Example 1. The results of the characteristic test are shown in Table 1.

Example 3 Using the same substrate and plasma polymerization apparatus as in Example 1, under reduced pressure,
1,1,3,3-tetramethyldisiloxane gas and O ₂
The pressure is 150 mT while aerating gas at a molar ratio of 1: 2.
Adjust and hold at orr, 110KHz, 0.5W / cm ²
Plasma was generated by applying low wave power and discharging to produce a polycarbonate resin substrate having a plasma polymerized film by plasma treating the substrate surface for 60 minutes. Then, while maintaining the pressure at 150 mTorr while passing only O ₂ gas under reduced pressure in the device, 110 KHz,
Plasma was generated by applying a low-wave-frequency power of 0.25 W / cm ² to cause discharge, and the substrate surface was plasma-treated for 3 minutes. The substrate temperature was maintained at about 50 ° C. during plasma polymerization and plasma treatment with O ₂ gas. A sputtered film was formed on this under the same conditions as in Example 1. The results of the characteristic test are shown in Table 1.

Example 4 Using the same substrate and plasma polymerization apparatus as in Example 1, under reduced pressure,
The pressure was raised to 18 while aerating 1,3,5,7-tetramethylcyclotetrasiloxane and O ₂ gas at a molar ratio of 1: 2.
Adjust and hold at 0mTorr, 110KHz, 0.5W /
Plasma is generated by applying a low frequency electric power of cm ² to discharge, and the substrate surface is plasma-treated for 60 minutes,
A polycarbonate resin substrate having a plasma polymerized film was obtained. Subsequently under reduced pressure at the same device to adjust the holding pressure to 200mTorr with aeration only O ₂ gas, 110KH
Plasma was generated by applying a low frequency electric power of z, 0.25 W / cm ² to cause discharge, and the substrate surface was plasma-treated for 3 minutes. The substrate temperature was maintained at about 50 ° C. during plasma polymerization and plasma treatment with O ₂ gas. A sputtered film was formed on this under the same conditions as in Example 1. The results of the characteristic test are shown in Table 1.

Comparative Example 1 Only the plasma polymerization was carried out under the same conditions using the same substrate and apparatus as in Example 1. The results of the characteristic test are shown in Table 2. Comparative Example 2 Only the plasma polymerization was performed under the same conditions using the same substrate and apparatus as in Example 2. The results of the characteristic test are shown in Table 2. Comparative Example 3 Only the plasma polymerization was carried out under the same conditions using the same substrate and apparatus as in Example 3. The results of the characteristic test are shown in Table 2. Comparative Example 4 Using the same substrate and apparatus as in Example 4, only plasma polymerization was performed under the same conditions. The results of the characteristic test are shown in Table 2. Comparative Example 5 Only the sputtering was performed using the same substrate and apparatus as in Example 1. The results of the characteristic test are shown in Table 2.

[0021]

EFFECTS OF THE INVENTION By coating the surface of a plastic product with a special multilayer structure, it has excellent scratch resistance, abrasion resistance, chemical resistance, charging characteristics, etc. and is suitable for use as a material for various optical applications. Plastics products are obtained.

[0022]

[Table 1]

[0023]

[Table 2]

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Claims (5)

[Claims] 1. A surface-coated plastic product having the following A film and B film laminated in this order on the surface. A film: A plasma polymerization film formed by plasma polymerization using a silicon compound as a monomer, having a film thickness of 0.1 μm to 10 μm, and having an atomic ratio of carbon to silicon contained in the range of 0.1 to 3. B film: SiO having a film thickness in the range of 0.1 μm to 3 μm
A coating film composed of x (x = 1.5 to 2.0). 2. The surface-coated plastics product according to claim 1, wherein the plasma-polymerized monomer of the A coating film is a silicon compound containing a carbon atom. 3. The surface-coated plastic product according to claim 1, wherein the plasma-polymerized monomer of the film A is a silicon compound containing carbon atoms and oxygen atoms. 4. The surface-coated plastic product according to claim 1, wherein the plasma-polymerized monomer of the A coating film is a silicon compound containing carbon atoms and nitrogen atoms. 5. The surface-coated plastic product according to claim 1, wherein the B coating film is formed by a sputtering method or a plasma CVD method.